Power-actuated hand-tool.



A. M. IRVINE.

POWER AGTUATED HAND TOOL.

APPLICATION FILED JULY 30, 1912.

Patented Feb. 11, 1913.

2 SHEETS-SHEET 1.

A. M. IRVINE.

POWER ACTUATED HAND TOOL.

APPLICATION FILED JULYSO, 1912.

Patented Feb. 11, 1913.

2 SHEETSSHBET 2,

14f THRIVE V.

ALBERT IBII. IRVINE, 0F PHILADELPHIA, PENNSYLVANIA.

POWERFACTUATEB HAND-TOOL.

Specification of Letters Patent.

Application filed July 30, 1912. Serial No. 712,280.

To all whom it may concern:

Be it known that I, ALBERT M. IRVINE, a citizen of the United States,residing at Philadel hia, county of Philadelphia, and State ofennsylvania, have invented anew and useful Improvement in Power-ActuatedHand-Tools, of which the followin is a full, clear, and exactdescription, re erence being had' to the accompanying drawings, whichform a part of this specification.

The object of my invention is'to produce a tool for riveting, calking,chipping, etc., in which the striking hammer-piston will be operatedpneumatically but which will be primarily actuated electrically. It iswell known that electrically operated tools of this character possesscertain advantages both with respect to cost of installation and economyand also that pneumatically operated hammers are usually of greaterefiiciency.

The more specific object of my invention is to provide a tool carrying amotor for generating the power required to reciprocate the hammer and bymeans of said motor compressing air which serves to propel the hammerforward against the chisel or other tool to be actuated.

A preferred embodiment of my invention is shown in the accompanyingdrawing, in which- Figure l is a longitudinal section through themachine, the front part of the piston chamber being omitted. Fig. 2 is aplan view partly broken away; Fig. 3 is a transverse section on the line33 of Fig. 1; Fig. 4 is a horizontal section on the line 47-4 of Fig. 3.r

The motive power for the machine is furnished by an electric motor I)which rotates on a vertical axis turning in bearings within the maincasing'a. The shaft of the motor carries a pinion c which drives a gear0? on the shaft e. The shaft 6 has a pinion f which drives a gear 9 onthe shaft h. The shaft it carries a crank disk c' which is connected, bymeans of a connecting rod 7', with a piston is reciprocable within acylinder Z forming part of the main casing. The rear end of the wall ofthe cylinder Z has two check valves m and n. The check valve m opensinward into the cylinder and communicates through a conduit 0 with theinterior of that part of the casing inclosing the motor 6. The checkvalve 12 opens outward from the cylinder and communicates with acompressed-air reservoir p extending from the rear of the casing a tothe front end thereof. The top wall of that part of the casing inclosingthe motor is provided with openings 1', thereby permitting atmosphericair to pass through the motor, the conduit 0, the check-valve m, andinto the compression chamber 8 back of the piston is. This current ofair performs also the useful function of cooling the motor.

The front of the casing is bell-shaped, the mouth of the bell openingforwardly. Secured to or integral with the casing is a handle 25.Slidable on the handle is a spring pressed thumb-piece u, which takesthe place of the throttle valve of an ordinary pneumatic hammer. Thisthumb piece is con nected, by means of a rod 21, with a bellcrank leverw, which carries a contact :12. The contact a: is adapted to contactwith the contact 4 on the normally stationary lever z. The electricalconpections are not shown, it being sufiicient to state that when thethumb-piece u is depressed by the operator, contact as engages contact yand closes the circuit to the motor.

When the motor is in operation it effects,

through the gearing described, the reciprocation of the piston is. Asthe piston moves toward the rear (to the right, Fig. 1) it compressesthe air in the compression cham her .9, thereby causing the valve 72. toopen and forcing the compressed air into the reservoir 7). As the pistonmoves toward the front (to the left, Fig. l) the valve n closes and thevalve m opens, drawing atmospheric air through the openings 1, the motor6, the conduit 0, and the valve m, into the compression chamber 8, whichair, on the next rearward movement of the piston, is in turn compressedand forced into the reservoir 72.

The bell-shaped front end of the casing a (which incloses the front endof the reservoir p) is closed by means of a head 5, which is threadedinto the mouth of the bell. This head has a forwardly extending annularflange 6, which is threaded into a sleeve 7.

The sleeve 7 has an inwardly projecting por-v tion which embraces ashell or piston-casing 8 inclosing the piston chamber. The shell 8, atits rear end, has an outwardly extending annular flange; and thisflange, together with a flange 9 on a block 10, is confined between theflange 6 of head 5 and the inwardly projecting front end of the sleeve7. The body of the block 10 extends within the Patented Feb. 1111,19313.

recess formed by the flange 6 on the head and is confined against saidhead. The block 10 is recessed to receive a transversely extendingreciprocable valve 11. A piston 12 is reciprocable in the pistonchamber.

The ports and passages whereby the valve controls the piston and thepiston the valve are not fully shown, as the same form no part of myinvention. It will be understood m that any of the known arrangements ofports and passages, such as characterize the ordinary pneumatic hammer,and which are well known to those skilled in the art, may be adopted. 1have, however, shown an inlet port 13 in the head 5; inlet ports 14 inthe block 10, aliningwith the port 13; and a groove 15 in the valve 11adapted, at one stroke of the valve, to register with the ports 14:.Thus when the valve is at one end of its stroke, pressure fluid isadmitted from the reservoir 30, through ports 13 and lt and groove 15,into the upper end of the piston chamber, where it acts upon the piston12 to propel it forwardly against the tool' (not shown) inserted in themouth of the casing 8. I have also shown an exhaust passage 16 in thehead 5, communicating direct with the atmosphere; a port 17 in the head5, communicating with the exhaust passage 16; ports 18 in the block 10,alining with the port 17; and a groove 19 in the valve 11 adapted, atthe other end of the valves stroke, toregister with the ports 18. Thuswhen the valve is at the other end of its stroke, the air will exhaust,from the rear of the piston chamber, through groove 19, ports I 18 and17, and passage 16 to the atmosphere.

As is well known, when the ordinary pneumatic hammer is withdrawn fromthe work, the reciprocation of the piston ceases. Under theseconditions, it is desirable that the operation of compressing air shallimmediately cease. Under ordinary circumstances, this will occur byreason of the operator purposely or naturally releasing the thumb-pieceu. At once the switch w-y is opened, shutting offthe current to themotor. In case, however, the pressure upon the thumb-piece should beretained, the following means are provided to automatically open theswitch. Within the casing a is a cylinder 20 having a piston 21 one sideof which is open to the interior of the reservoir 1). The piston rod 22is connected to one end of the normally stationary lever 2 carrying thecontact 7. A spring 23 is confined between the closed end of thecylinder 20 and the pistonhead 21 and forces the latter against a stop24. This spring is strong enough to counterbalance the normal maximumpressure in the reservoir p and thus the lever a is held in it, normalstationary position. If, however, the thumb-piece u should be helddepressed after the hammer a5 is withdrawn from the work, the motor 6nesaeae will continue to actuate the air-compressing piston k. The aircompressed thereby and forced into the reservoir 12 having no outlet,the pressure within the reservoir will rise until it overcomes thespring 23, and actuates the piston 21 to move the lever 2 so as towithdraw the contact 3/ from the contact 02, thus opening the circuit tothe motor and stopping the operation of the machine.

Having now fully described my invention, what 1 claim and desire toprotect by Letters Patent is: I

-1. In a power-actuated hand tool, the combination with a main casing,of an electric motor, an air compressing member and connections betweenthe motor and said member whereby the latter is reciprocated, and acompressed air reservoir adapted to receive and store the air compressedby the air compressing member,-all arranged in said casing, a pistoncasing connected with the main casing, a'- hammer-piston therein adaptedto be actuated by the air in the reservoir, a handle on the main casing,and-a j switch controlling the current to the motor..-

2. In a power-actuated hand-tool, the combination with a main casing,ofan electric motor, an air compressing member and connections betweenthe motor and said member whereby the latter is reciprocated, and acompressed air reservoir adapted to receive and store the air compressedby the air compressing member all arranged in said casing, a pistonchamber connected wlth; the main casing, a hammer-piston therein, avalve controlling the admission of air from the reservoir to the pistonchamber, a handle on the main casing, and a switch controlling thecurrent to the motor.

3. In a power-actuated hand tool, the combination with a main casing, ofan electric motor, an air compressing member and connections between themotor and said member whereby the latter is reciprocated, and acompressed air reservoir adapted to receive and store the air compressedby the air compressing member, all arranged in said casing, a pistonchamber connected with the main casing, a hammer-piston therein, inletports communicating respectively with the rear of the piston chamber andwith the reservoir, exhaust ports communicating respectively with therear of the piston chamber and with the atmosphere, a valve adapted toalternately connect the inlet ports and 20 the exhaust ports, a handleon the main casing, and a switch controlling the current to the motor. v

4. In a power-actuated hand tool, the combinationwith a main casing, ofan electric motor, an air compression chamber, a piston therein,connections between the motor and the piston whereby the latter isreciprocated, and a compressed air reservoir, all arranged in thecasing, a valve adapted to admit air into the compression chamber in thesuction stroke of the piston, a valve adapted to admit air into thereservoir from the compression chamber in the compression stroke of thepiston, a piston.casing connected with the main casing, a hammer pistontherein adapted to be actuated by the air in the reservoir, a handle onthe main casing, and a switch controlling the current to the motor. 7

5. In a power-actuated hand-tool, the combination with an electricmotor, a piston, and a gearing between the motor and piston adapted toactuate the latter; of a main casing having formed therein chamhers forthe motor and caring, a compression chamber on one si e of the piston, acompressed air reservoir, a conduit connecting the motorchamber and thecompression chamber, and openings through the casing into the motorchamber; a valve between said conduit and the compression chamberadapted to open on the exhaust stroke of the piston, a valve betweensaid reservoir and the compression chamber adapted to open on thecompression stroke of the piston, and a hammer piston adapted to beactuated by the air in the reservoir.

6. In a power-actuated hand tool, the combination with a main casing, ofanelectric motor within the casing, an air compressing member,connections between the motor and said member whereby the latter is l'eciprocated, a compressed air reservoir adapted to receive and storethe air compressed by said member, a handle formed on the casing, aswitch controlling the current to the motor, a spring pressed thumbpiece on the handle, and means connecting the thumb-piece and theswitch.

7. In a power actuated .hand tool, the

combination with a main casing, of an elec{ tric' motor within thecasing, an air compressing member, connections between the motor andsaid member whereby the latter adapted to be actuated thereby when thepressure rises beyond the desired maximum, and means actuated by thepiston and adapted to open the switch.

8. In a. power-actuated hand tool, the combination with a main casing,of an electric motor within the casing, an air compressing member,connections between the motor and said member whereby the latter isreciprocated, a com ressed air reservoir adapted to receive an store theair com! pressed by said member, a normally stationary switch contact, ahandle formed on the casing, a spring-pressed thumb piece on the handle,a second switch contact connected with the thumb piece and adapted to bemoved thereby into contact with the first switchcontact, aspring-pressed piston open to the pressure fluid in the reservoir, andmeans connecting the piston and the first switch contact and adaptedwhen operated to move the latter away from the second switch contact.

9. In a power actuated hand tool, the combination with an electricmotor, a switch controlling the current to the motor, a piston, andgearing between the motor and piston adapted to actuate the latter; of amain casing having formed therein chambe'rs for'the motor and gearing, acompression chamber on one side of the piston, and a compressed airreservoir; a handle on the main casing, a switch controlling the currentto the motor, a valve establishing communication between the compressionchamher and the atmosphere adapted to 0 en on the exhaust stroke of thepiston, a va ve between said reservoir and the compression chamberadapted to open on the compression stroke of the piston, a casingforming a piston chamber connected to the main casing, and a hammerpiston in said chamber adapted to be actuated by the air in the Vreservoir.

In testimony of which invention, I have hereunto set my hand, atPhiladelphia, on this 26th day of July, 1912.

7 ALBERT M. IRVINE.

Vitnesses:

M. M. HaMmroN, E. E. WALL.

